A couple of people told me recently that their company ID cards (RFID based) started to not work anymore. When I asked them if they had called their security company, they said they did and the recommendation was to not keep the company badge in the wallet.
However most people put the access card into the wallet. The problem with that is that it can get in touch with credit cards which can cause demagnetization or desensitization. We call it the demagnitized card.
The card in wallet problem
When looking on Quora, people report similar things: “I have three different ID badges, all with RFID in them. They are all currently in my wallet. When I try to use them, they interfere with each other and the scanner does not read my card. This happens even when I take all three out, put them together and try to scan a card. When I scan the correct card alone, it works flawlessly. Is there I way I can address this?”
Some people have these issues especially with hotel keycards which are based on 125khz (and especially easy to hack by the way). There are speculations around if the smartphone can actually cause a demagnetized card.
It seems like this is happening specifically with low frequency cards. As a workaround (besides buying more expensive cards or readers), people suggest to use aluminum foil and cover the card with that.
Possible solutions to avoid a demagnetized card
Before jumping ahead with more expensive solutions, you can also go to your security department and ask if they activated the anti- RFID Tag collision algorithm on their readers. Basically this allows different ways to keep radio waves from one device from interfering with radio waves from another device.
Not going too deep into this, but for example an adaptive hierarchical artificial immune system and build the basis for such an algorithm.
If you want to go more professional to prevent a demagnetized card, there are even RFID blocking wallets.
One of the more crazy solutions we’ve found is to extract the RFID coil and chip from the card and just mount it into your smartphone – that way you can store your RFID transit card in your smartphone. Some people call this RFID transplantation.
Probably most likely the best idea to keep it old school and if you have to wear a badge, wear it like a government employee in a plastic enclosure tagged to your chest. Your security guys will love it! However we doubt this is the future.